[The Elf-warrior]

I wish the winged steeds the Nazgûl used were really stupid and kept trying eat the Nazgûl.

Your wish is granted. Unfortunately one of the steeds dropped the Witch-King into the Dead Marshes. He found Frodo, Sam, and Gollum and brought them to an Orc patrol after removing the One Ring. They all went to Barad-Dur, where the Hobbits were tortured for years. With the power of the Ring Sauron conquered all of Middle-Earth and ruled it for thousands of years.

I wish that Theoden had survived the War of the Ring.